/Engine/Source/Runtime/Experimental/Chaos/Public/Chaos/Island/IslandGroupManager.h
Register a constraint type with the manager. This will create a ConstraintContainerSolver for the ConstraintsContainer. Constraints are solved in Priority order with lower priorities first, so higher priorities "win".
void AddConstraintContainer ( [FPBDConstraintContainer](API\Runtime\Chaos\Chaos\FPBDConstraintContainer) & ConstraintContainer, const int32 Priority )